Chemosensory dysfunction continues to affect 2 million adult Americans. In an attempt to deal with this problem, the previous grant developed safe biopsy techniques for human olfactory and gustatory epithelum, defined normal ultrastructure for both, and confirmed the hypothesis that ultrastructural changes occurred in dysfunctional patients. During the proposed renewal, we will focus on several specific dysfunctional states: Alzheimer's disease, post-viral anosmia, post-traumatic anosmia, post-laryngectomy "anosmia", and ideopathic dysgeusia. We intend to study the ultrastructural changes in humans in conjunction with animal studies carried out by other members of the program project (e.g. studies with OMP-- Project #1, Na/K ATPase--Project #3, neuropeptide studies-- Project #5, and 3-dimensional computer reconstructions--Project #6). All of this should aid us in further understanding the dynamic changes in chemosensory receptors in humans. Thus, this project will have major clinical as well as basic science components.